This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Studies under this project title are focused on a variety of ion channels including Na, Cl and proton channels. These channels are structurally distinct from K channels and promise to lead us to a more complete general understanding of ion selectivity. These proteins have yielded preliminary crystals that need improvement. We will focus efforts over the next year on identifying more highly ordered crystals.